Conversion material

Abstract

The invention describes a glass and a glass-ceramic which at least includes the constituents SiO 2 , Al 2 O 3 and Y 2 O 3 and is preferably doped with rare earth ions. The weight ratio between the weight of Y 2 O 3 and the total weight of SiO 2 , Al 2 O 3 and Y 2 O 3 is at least 0.2, preferably at least 0.4 or more. The rare earth ions can preferably be incorporated in crystal phases which are precipitated out of glass with a high yttrium content.

1. A light source comprising a light emitter and a conversion material for converting light from the light emitter of a first wavelength spectrum into light of a second wavelength spectrum, wherein said conversion material comprises a glass-ceramic that is configured as a molten and heat-treated material having precipitated crystals therein and comprises at least the constituents SiO 2 , Al 2 O 3 , Y 2 O 3 , and rare earth ions, wherein a weight ratio between the weight of Y 2 O 3  and the total weight of SiO 2 , Al 2 O 3  and Y 2 O 3  is at least 0.2. 
     
     
       2. The light source of  claim 1 , wherein said weight ratio between the weight of Y 2 O 3  and the total weight of SiO 2 , Al 2 O 3  and Y 2 O 3  is at least 0.3. 
     
     
       3. The light source of  claim 1 , wherein said weight ratio between the weight of Y 2 O 3  and the total weight of SiO 2 , Al 2 O 3  and Y 2 O 3  is at least 0.4. 
     
     
       4. The light source of  claim 1 , in which a weight ratio between the weight of SiO 2  and the total weight of SiO 2 , Al 2 O 3  and Y 2 O 3  is at most 0.5. 
     
     
       5. The light source of  claim 1 , in which a weight ratio between the weight of Al 2 O 3  and the total weight of SiO 2 , Al 2 O 3  and Y 2 O 3  is at most 0.6. 
     
     
       6. The light source of  claim 1 , wherein said glass ceramic comprises at least 0.1% by weight (based on oxide) of a doping with at least one rare earth ion. 
     
     
       7. The light source of  claim 1 , wherein said glass ceramic comprises a doping of at least one rare earth ion which is selected from the group consisting of Ce, Pr, Nd, Sm, Eu, Gd, Tb, Er, Tm, Yb, Dy and La. 
     
     
       8. The light source of  claim 1 , wherein said glass ceramic further comprises B 2 O 3 . 
     
     
       9. The light source of  claim 8 , wherein said glass ceramic comprises (in wt-%, based on oxide): 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   SiO 2   
                    5–50 
                 
                     
                   Al 2 O 3   
                    5–50 
                 
                     
                   Y 2 O 3   
                   10–80 
                 
                     
                   B 2 O 3   
                    0–20 
                 
                     
                   rare earths 
                   0.1–30. 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
               
            
           
         
       
     
     
       10. The light source of  claim 9 , wherein said glass ceramic comprises (in wt.-%, based on oxide): 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   SiO 2   
                   10–40 
                 
                     
                   Al 2 O 3   
                   10–40 
                 
                     
                   Y 2 O 3   
                   20–70 
                 
                     
                   B 2 O 3   
                    1–15 
                 
                     
                   rare earths 
                   0.5–15. 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
               
            
           
         
       
     
     
       11. The light source of  claim 10 , wherein said glass ceramic comprises (in wt.-%, based on oxide): 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   SiO 2   
                   15–35 
                 
                     
                   Al 2 O 3   
                   15–35 
                 
                     
                   Y 2 O 3   
                   25–60 
                 
                     
                   B 2 O 3   
                    1–10 
                 
                     
                   rare earths 
                     1–15. 
                 
                     
                     
                 
             
                
               
               
                
                
                
                
                
                
               
            
           
         
       
     
     
       12. The light source of  claim 1 , wherein said glass ceramic further comprises additions of at least one component selected from the group consisting of SrO, BaO, CaO, P 2 O 5 , Ga 2 O 3 , Na 2 O, K 2 O, Li 2 O, TiO 2 , ZrO 2  and Ta 2 O 5 . 
     
     
       13. The light source of  claim 1 , wherein said glass ceramic comprises less than 5% by weight of ZrO 2 . 
     
     
       14. The light source of  claim 1 , wherein said glass ceramic comprises at least one crystalline phase which at least partially incorporates rare earth ions. 
     
     
       15. The light source of  claim 14 , wherein said glass ceramic comprises at least one crystalline phase including as a constituent yttrium ions which are at least partially replaced by rare earth ions. 
     
     
       16. The light source of  claim 14 , wherein said glass ceramic comprises at least one crystalline phase selected from the group consisting of Y 3 Al 5 O 12 , Y 2 SiO 5 , Y 2 Si 2 O 7 , SrAl 2 O 4 , BaMgAl 10 O 17 , Sr 2 P 2 O 7 , Sr 4 Al 14 O 25  and YBO 3 , said at least one crystalline phase serving at least partially as a host phase for incorporating at least one rare earth ion. 
     
     
       17. The light source of  claim 14 , wherein said glass ceramic comprises at least one crystalline phase dispersed within a residual glass, wherein rare earth ions are incorporated in said residual glass. 
     
     
       18. The light source of  claim 1 , wherein the conversion material is disposed in direct contact with the light emitter. 
     
     
       19. The light source of  claim 18 , wherein said light emitter comprises an LED. 
     
     
       20. The light source of  claim 19 , wherein said conversion material is deposited directly onto said LED while in said molten state. 
     
     
       21. A method for converting a first radiation emitted by a light emitter into a different radiation by passing the light from the light emitter through a conversion material comprising a glass ceramic, and configuring the glass ceramic as a molten and heat-treated material having precipitated crystals therein and comprises at least the constituents SiO 2 , Al 2 O 3 , and Y 2 O 3 , and rare earth ions, wherein a weight ratio between the weight of Y 2 O 3  and the total weight of SiO 2 , Al 2 O 3  and Y 2 O 3  is at least 0.2. 
     
     
       22. The method of  claim 21 , wherein the glass ceramic is further configured so that a weight ratio between the weight of SiO 2  and the total weight of SiO 2 , Al 2 O 3  and Y 2 O 3  is at most 0.5, and wherein a weight ratio between the weight of Al 2 O 3  and the total weight of SiO 2 , Al 2 O 3  and Y 2 O 3  is at most 0.6.